CT Scan – Abdomen and Pelvis

About a CT scan of the abdomen and pelvis

A CT of the abdomen and pelvis covers the whole of the tummy, from the bottom of the ribs down to the top of the legs. As well as the upper abdominal organs, such as the liver, pancreas and kidneys, it includes the lower bowel, appendix, bladder, the womb and ovaries or the prostate, and the bones of the pelvis and lower spine. A CT (computed tomography) scan uses X-rays and a computer to make detailed cross-section pictures, which can be viewed from any angle.

Because many problems in the tummy can affect more than one area, this is one of the most commonly requested CT scans. It may be used to investigate:

• tummy pain, including possible appendicitis or diverticulitis
• changes in bowel habit, unexplained weight loss or a lump
• kidney, ureter and bladder problems
• suspected cancer, to find out whether it has spread (staging), or to check how treatment is working
• collections of fluid or pus (abscesses), hernias and blockages
• problems after surgery

For kidney stones, a low-dose CT KUB without contrast is usually used, and for a detailed look at the bowel lining, a CT virtual colonoscopy may be more suitable. If the chest also needs scanning, for example to stage a cancer, a CT of the chest, abdomen and pelvis (CAP) is used. Your referrer will say which scan is needed.

What happens during the scan

You lie on your back on the scanner bed, usually with your arms raised above your head. The bed moves slowly through a short, open ring while your tummy and pelvis are is scanned. The radiographer controls the scanner from the next room, but can see, hear and talk to you throughout. You will be asked to hold your breath for a few seconds at a time. The scan itself takes only a few minutes, although with preparation the appointment usually takes longer.

For some CT scans, an injection of contrast dye is given through a small cannula in a vein, usually in your arm or hand, to make blood vessels and organs show up more clearly. CT contrast contains iodine. As it goes in you may feel warm and flushed, notice a metallic taste, or feel as if you are passing urine; these feelings pass within a minute or two. Allergic reactions are uncommon, and you may be asked to wait for up to 30 minutes afterwards. Where contrast is needed, it is charged separately.

Is CT safe?

CT uses X-rays, which are a type of ionising radiation. A CT of the abdomen and pelvis gives a typical dose of about 10 mSv, similar to the natural background radiation you would receive from the environment over about 4.5 years. The risk from a single scan is very small, and every CT scan is checked by a radiologist or radiographer to make sure the benefit of the scan outweighs the risk, as required by the Ionising Radiation (Medical Exposure) Regulations. If you have had other CT scans recently, tell us when you book.